This invention relates to new aromatic amidocarboxylic acid derivatives. More particularly, this invention relates to cinnamoylaminophenylalkylcarboxylic acid derivatives and cinnamoylaminophenoxyalkylcarboxylic acid derivatives which exhibit a strong antiallergic effect when administered orally to mammalia including humans.
Hitherto, disodium chromoglycate was known as an antiallergic agent effective for inhibiting release of chemical mediators from cells caused by an antigen-antibody reaction. However, such pharmacological effect is not at all expected when this compound is administered orally, and the extent to which this compound is applicable is naturally limited. Thus, development of an antiallergic agent which can exhibit a satisfactory therapeutic effect by oral administration has long been demanded in the field of medicine.
On the other hand, unsubstituted cinnamoylaminobenzoic acid which is an analogue of the end products of the present invention was already synthetized by Reinicke and publicly known (Liebig's Annalen der Chemie, vol. 341, pages 94-96). However, this compound shows only a slightly weak antiallergic effect when administered orally to mammalia, and so was hardly applicable as practically effective medicine. As a result of our research carried out on antiallergic effects of various cinnamoylaminobenzoic acid derivatives, we found that certain kinds of nucleus-substituted cinnamoylaminobenzoic acid derivatives had a strong antiallergic effect. An invention based on the above finding was already applied for by us in Japan as Japanese Patent Appln. No. 7359/73. As a result of our further research carried out on antiallergic effects of cinnamoylaminophenylalkylcarboxylic acid derivatives and cinnamoylaminophenoxyalkylcarboxylic acid derivatives, it has now been found that a series of these amidocarboxylic acid derivatives possess an extremely strong antiallergic effect.